I have a multiple View Controllers and I want to set the font color of all to red.
[[UINavigationBar appearance] setFont:[UIFont boldSystemFontOfSize:12.0]]
Doing this on iOS 8+ and in Swift. There isn't a setTitleTextAttributes for the appearance object. Instead, do this:
setTitleTextAttributes
UINavigationBar.appearance().titleTextAttributes = [NSFontAttributeName : AppTheme.fontWithSize(18)]